JP6408664B2 - COMMUNICATION DEVICE, COMMUNICATION METHOD, AND COMMUNICATION SYSTEM - Google Patents

Description

  The present invention relates to a communication device, a communication method, and a communication system that limit transmission power.

Conventionally, in a communication system that performs communication in a certain frequency band, the maximum transmission power of a radio signal transmitted by a communication device is specified. For example, in 3GPP, the maximum transmission power when a mobile station transmits a radio signal is defined (for example, Non-Patent Document 1 and Non-Patent Document 2). Specifically, the PUSCH transmission power of the mobile station is limited by any of the following formulas (1) to (3), and a value with a small power control value such as maximum transmission power and path loss is set as the maximum transmission power ( Non-patent document 2).

  In ARIB, when the occupied frequency bandwidth exceeds 288 kHz, the average power in burst radiated in a band of ± 96 kHz centered on a frequency 900 kHz away from the center frequency of the carrier wave is −23.8 [dBm / MHz] ( 800 nW) or less (Non-Patent Document 3). Furthermore, ARIB stipulates that the average power in a burst radiated in a band of ± 96 kHz centered on a frequency separated by 1200 kHz is −28.9 [dBm / MHz] (250 nW) or less.

3GPP TS 36.101 Ver. 9.0.0 “LTE; Evolved Universal Terrestrial Radio Access (U-UTRA); User Equipment (UE) radio transmission and reception” 3GPP TS 36.213 Ver. 10.4.0 “LTE; Evolved Universal Terrestrial Radio Access (U-UTRA); Physical layer procedures” ARIB RCR STD-28 “Second Generation Cordless Telephone System”

  For example, it is conceivable to perform communication such as the TD-LTE system in a band from 1884.5 MHz to 1893.5 MHz (hereinafter referred to as 9 MHz band) allocated as a frequency band of public PHS. In this case, if the mobile station transmits with the maximum transmission power of LTE according to the 3GPP regulations (Non-patent Document 1 etc.), the leakage power regulations (for example, the ARIB regulations (Non-patent Document 3)) in other adjacent systems must be satisfied. I can't. Then, spurious interference occurs in the adjacent digital cordless band (band of 1893.5 MHz or more and less than 1906.1 MHz) and 1.7G mobile phone band (band of less than 1879.9 MHz).

  Accordingly, an object of the present invention made in view of the above problems is a communication apparatus, a communication method, and an communication apparatus capable of setting an optimum maximum transmission power while suppressing spurious interference to a band of an adjacent system. And providing a communication system.

  In order to solve the above-described problem, a communication apparatus according to the present invention is a communication apparatus that performs radio communication using the LTE system, and includes a communication unit that transmits a transmission signal in a predetermined transmission frequency band, and the transmission frequency band includes other systems. Is adjacent to the adjacent frequency band for which there is no guard band between the transmission frequency band and the adjacent frequency band, and a band away from the center of the transmission frequency band by a certain frequency is in the adjacent frequency band When the transmission unit transmits the transmission signal, the maximum transmission power is limited, and the transmission power radiated to the band apart from the predetermined frequency is set to a predetermined value or less.

  The communication apparatus according to the present invention may be configured such that a band separated from the fixed frequency is a first band, a band further away from the fixed frequency is a second band, and the first band and the second band are the adjacent frequencies. In the band, the predetermined value is a first predetermined value, a value lower than the first predetermined value is a second predetermined value, and the communication unit is radiated to the second band when transmitting the transmission signal. The transmission power is set to be equal to or lower than the second predetermined value.

  Further, in the communication device according to the present invention, the transmission power radiated to the first band and the second band by the communication unit is the first band and the second band corresponding to a spectrum mask defined by 3GPP. It is characterized by being smaller than the transmission power.

  A communication method according to the present invention is a communication method of a communication apparatus that performs radio communication using the LTE scheme and transmits a transmission signal in a predetermined transmission frequency band, and the transmission frequency band is an adjacent frequency band for another system. Adjacent, there is no guard band between the transmission frequency band and the adjacent frequency band, and a band away from the center of the transmission frequency band by a certain frequency is in the adjacent frequency band, and transmits the transmission signal. In this case, there is provided a step of limiting the maximum transmission power and setting the transmission power radiated to the band apart from the predetermined frequency to a predetermined value or less.

  A communication system according to the present invention is a communication system that includes a communication device and a partner communication device, and performs wireless communication by LTE, wherein the communication device transmits a transmission signal in a predetermined transmission frequency band, and the transmission frequency band Is adjacent to an adjacent frequency band for another system, there is no guard band between the transmission frequency band and the adjacent frequency band, and a band apart from the center of the transmission frequency band by a certain frequency is the adjacent band. In the frequency band, when the communication device transmits the transmission signal, the maximum transmission power is limited, and the transmission power radiated to the band apart from the predetermined frequency is set to a predetermined value or less.

  According to the communication device, the communication method, and the communication system of the present invention, it is possible to set an optimum maximum transmission power while suppressing spurious interference to a band of an adjacent system.

1 is a schematic diagram of a communication system according to an embodiment of the present invention. It is a block diagram of the base station which concerns on one Embodiment of this invention. It is a block diagram of the mobile station which concerns on one Embodiment of this invention. It is an arrangement | positioning schematic diagram of the frequency band which the communication system which concerns on one Embodiment of this invention uses. It is a schematic diagram of the restriction | limiting of the maximum transmission power which concerns on one Embodiment of this invention. FIG. 6 is a schematic diagram of a limitation on maximum transmission power related to a line 501 in FIG. 5. FIG. 6 is a schematic diagram of the limitation on the maximum transmission power related to the line 502 in FIG. 5. FIG. 6 is a schematic diagram of restriction on maximum transmission power related to a line 503 in FIG. 5.

  Embodiments of the present invention will be described below.

(Embodiment)
FIG. 1 is a schematic diagram of a communication system 1 according to an embodiment of the present invention. A communication system 1 according to an embodiment of the present invention includes a plurality of communication devices. For example, as shown in FIG. 1, the communication system 1 includes a communication device 10 (base station 10) and a communication device 11 (mobile station 11). The communication device 10 and the communication device 11 communicate wirelessly.

  The communication system 1 is a system that employs a communication method such as TD-LTE or LTE. Hereinafter, in the present embodiment, the communication system 1 will be described assuming that a TD-LTE communication method is employed. Further, the communication system 1 performs wireless communication by arranging carriers having a bandwidth (first frequency bandwidth) of 5 MHz (effective bandwidth is 4.5 MHz) in the 9 MHz band (second frequency band).

  FIG. 2 is a block diagram of the base station 10 according to an embodiment of the present invention. As shown in FIG. 2, the base station 10 includes a base station communication unit 101, a base station baseband unit 102, and a base station control unit 103. Base station communication section 101 and base station baseband section 102 are connected to base station control section 103.

  The base station communication unit 101 transmits and receives radio signals (data) to and from the mobile station 11 via an antenna. The base station communication unit 101 performs amplification and down-conversion with low noise on the received radio signal (reception signal), and sends the processed signal to the base station baseband unit 102. In addition, the base station communication unit 101 performs up-conversion and amplification on the baseband signal received from the base station baseband unit 102 to generate a radio signal (transmission signal). Then, the base station communication unit 101 transmits the radio signal to the mobile station 11 via the antenna.

  The base station baseband unit 102 demodulates the received signal by performing AD conversion, fast Fourier transform, and the like on the signal received from the base station communication unit 101, and extracts the baseband signal. Then, the base station baseband unit 102 sends a baseband signal to the base station control unit 103. The base station baseband unit 102 modulates the baseband signal by performing inverse fast Fourier transform, DA conversion, and the like on the baseband signal generated by the base station control unit 103. Then, the modulated baseband signal is sent to the base station communication unit 101.

  The base station control unit 103 controls and manages the entire base station 10 including each functional block of the base station 10. The base station control unit 103 is configured as software executed on any suitable processor such as a CPU (Central Processing Unit), or by a dedicated processor (for example, DSP (Digital Signal Processor)) specialized for each process. It can also be configured.

  The base station control unit 103 uses a carrier having a first frequency bandwidth in order to realize wireless communication between the base station 10 and the mobile station 11. Specifically, the base station control unit 103 allocates the used downlink radio resources and the used uplink radio resources that are part of the carrier to the mobile station 11 (and other mobile stations connected to the base station 10). The used downlink radio resource is a radio resource that the base station uses in downlink communication (downlink) with the mobile station. The used uplink radio resource is a radio resource used by the mobile station in uplink communication (uplink) with the base station. Then, the base station control unit 103 communicates with the mobile station 11 using the allocated use downlink radio resources and use uplink radio resources. In addition, the base station control unit 103 transmits the information on the assigned downlink radio resources and uplink uplink radio resources to the mobile station 11 (and other mobile stations connected to the base station 10) via the base station communication unit 101. Send.

  FIG. 3 shows a block diagram of the mobile station 11 according to an embodiment of the present invention. As shown in FIG. 3, the mobile station 11 includes a mobile station communication unit 111, a mobile station baseband unit 112, and a mobile station control unit 113. The mobile station communication unit 111 and the mobile station baseband unit 112 are connected to the mobile station control unit 113.

  The mobile station communication unit 111 transmits and receives radio signals (data) to and from the base station 10 via an antenna. The mobile station communication unit 111 performs amplification and down-conversion with low noise on the received radio signal (reception signal), and sends the processed signal to the mobile station baseband unit 112. In addition, the mobile station communication unit 111 performs up-conversion and amplification on the baseband signal received from the mobile station baseband unit 112 to generate a radio signal (transmission signal). Then, the mobile station communication unit 111 transmits the radio signal to the base station 10 via the antenna.

  The mobile station baseband unit 112 demodulates the received signal by performing AD conversion, fast Fourier transform, and the like on the signal received from the mobile station communication unit 111, and extracts the baseband signal. Then, the mobile station baseband unit 112 sends a baseband signal to the mobile station control unit 113. The mobile station baseband unit 112 modulates the baseband signal by performing inverse fast Fourier transform, DA conversion, and the like on the baseband signal generated by the mobile station control unit 113. Then, the modulated baseband signal is sent to the mobile station communication unit 111.

  The mobile station control unit 113 controls and manages the entire mobile station 11 including each functional block of the mobile station 11. The mobile station control unit 113 is configured as software executed on any suitable processor such as a CPU (Central Processing Unit), or by a dedicated processor (for example, DSP (Digital Signal Processor)) specialized for each process. It can also be configured.

  The mobile station control unit 113 determines the radio resource to be used based on the allocation information of the used downlink radio resource and the used uplink radio resource in the carrier received from the base station 10. Then, the mobile station control unit 113 performs radio communication with the base station 10 by the mobile station communication unit 111 and the mobile station baseband unit 112 using the determined radio resource.

  Next, the uplink radio resource allocation of the base station 10 in the present embodiment will be described in detail. As described above, the transmission frequency band used as the uplink radio resource is set within the 9 MHz band. In the vicinity of the 9 MHz band, as shown in FIG. 4A, a 1.7 G mobile phone band, a guard band band, a public PHS band (9 MHz band), a digital cordless telephone band, a public PHS band, a guard band band, 2G Mobile phone bands are less than 1879.9 MHz, 1879.9 MHz to 1884.5 MHz, 1884.5 MHz to 1893.5 MHz, 1893.5 MHz to 1906.1 MHz, 1906.1 to 1915.7 MHz, 1915.7 MHz to 1920 MHz, 1920 MHz or more, respectively. Allocated to the area.

  FIG. 4B shows a schematic diagram of carriers arranged in the 9 MHz band in the communication system 1. The base station control unit 103 of the base station 10 allocates 15 RBs in the region 401 for PUSCH (Physical Uplink Shared Channel (uplink shared channel)). Further, the base station control unit 103 allocates a part of each 5RB of the area 402 and the area 403 for PUCCH (Physical Uplink Control Channel (uplink control channel)), that is, a channel for communicating control data. The allocation of the PUSCH and PUCCH is based on 3GPP rules (3GPP TS 36.211 Ver. 9.0.0). Here, the base station control unit 103 allocates the second half slot of the RB having the lowest frequency in the region 402 and the RB having the third lowest frequency to the PUCCH. The latter half slot is a slot in the time domain of 0.5 ms in the latter half of 1 RB (2 slots). Also, the base station control unit 103 allocates the first half slot of the RB having the third lowest frequency and the 2RB having the fourth to fifth lowest frequency in the region 403 for PUCCH. The first half slot is a slot in the time domain of 0.5 ms in the first half of 1 RB (2 slots). As shown in FIG. 4B, the position of each RB included in the carrier is indicated by a number (hereinafter referred to as RB number), and is set to 0 to 24 in ascending order of frequency.

  Here, one end of the 9 MHz band is adjacent to the guard band, and the other end is adjacent to the digital cordless telephone band which is another system. Therefore, when the mobile station 11 transmits a radio signal with the maximum transmission power specified by 3GPP using the PUSCH resources to the maximum, power may leak to the adjacent digital cordless telephone band and spurious interference may occur. is there.

  Therefore, in the present embodiment, the mobile station control unit 113 of the mobile station 11 uses the position of one end of the transmission frequency band (PUSCH allocation position) for transmitting a radio signal, the bandwidth of the transmission frequency band (RB allocation number), and The maximum transmission power value of the radio signal is set according to Specifically, the mobile station control unit 113 predetermines the maximum transmission power that satisfies the leakage power rule in the adjacent channel, depending on the PUSCH allocation position and the number of RB allocations.

FIG. 5 shows a conceptual diagram of power limitation depending on the allocation position and the number of RB allocations. Each line 501-503 in FIG. 5 is demonstrated in detail using FIGS. 6-8, respectively. FIG. 6 is a diagram in which information related to the line 501 in FIG. 5 is extracted. Line 501 indicates the spectrum of the predicted value of the maximum transmission power when the allocation position is RB numbers 16 to 19 and the number of RB allocations is 4 RBs. The line 501 is calculated by scaling the mask width by the number of assigned RBs based on the spectrum mask defined in 3GPP. In this case, the in-burst average power radiated within a ± 96 kHz band (band 511) centered at a frequency 900 kHz away from the center frequency of the carrier wave is −23.8 [dBm / MHz] or less. Note that the center frequency of the carrier wave is a position (approximately 1893.35 MHz) on the left side of 150 kHz from the right end of the 9 MHz band in FIG. Further, the average power in burst radiated in a band of ± 96 kHz (band 521) centered on a frequency distant from the center frequency of the carrier by 1200 kHz is −2.
It becomes 8.9 [dBm / MHz] or less. Therefore, when the number of allocated RBs is 4 RBs, the mobile station control unit 113 does not limit the maximum transmission power from 17.5 [dBm / MHz] (250 mW), which is a 3GPP standard.

  FIG. 7 is a diagram in which information related to the line 502 is extracted from FIG. A line 502 indicates a spectrum of a predicted value of the maximum transmission power when the allocation position is RB numbers 14 to 19 and the allocation RB is 6 RBs. Similar to the line 501, the line 502 is calculated by scaling the mask width by the number of assigned RBs based on the spectrum mask defined in 3GPP. In this case, the mobile station control unit 113 sets the maximum transmission power to be lowered by 10 dB from 17.5 [dBm / MHz] defined in 3GPP. That is, the mobile station control unit 113 sets the maximum transmission power to 7.5 [dBm / MHz]. By setting in this way, the average power in burst radiated to the band 511 is set to −23.8 [dBm / MHz] or less. Further, the average power in the burst radiated to the band 521 is set to −28.9 [dBm / MHz] or less.

  FIG. 8 is a diagram in which information related to the line 503 is extracted from FIG. Line 503 indicates the spectrum of the predicted value of the maximum transmission power when the allocation position is RB numbers 5 to 19 and the number of RB allocations is 15 RBs. Like the line 501, the line 503 is based on a spectrum mask defined in 3GPP. In this case, the mobile station control unit 113 sets the maximum transmission power to be lowered by 20 dB from 17.5 [dBm / MHz] defined in 3GPP. That is, the mobile station control unit 113 sets the maximum transmission power to −2.5 [dBm / MHz]. By setting in this way, the average power in burst radiated to the band 511 is set to −23.8 [dBm / MHz] or less. Further, the average power in the burst radiated to the band 521 is set to −28.9 [dBm / MHz] or less. In FIG. 5 (and FIGS. 6 to 8), three patterns of allocation positions and allocation RBs are shown, but the power limit value can be determined in the same manner even if other allocation positions and the number of RB allocations are used. .

  In FIG. 5, the spectrum of the maximum value of the transmission power is predicted based on the 3GPP spectrum mask, and the power limit value of the mobile station control unit 113 is determined. However, the present invention is not limited to this. For example, the maximum transmission power may be determined by actual measurement in the mobile station 11, or a spectrum mask may be separately defined according to the standard.

  Then, the mobile station control unit 113 sets the lowest value among the maximum transmission power value thus determined and any one of the formulas (1) to (3) defined in advance by the standard to the maximum transmission power. Determine as value.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, the functions included in each means, each step, etc. can be rearranged so that there is no logical contradiction, and a plurality of means, steps, etc. can be combined or divided into one. .

1 communication system 10 base station (communication device)
11 Mobile station (communication equipment)
DESCRIPTION OF SYMBOLS 101 Base station communication part 102 Base station baseband part 103 Base station control part 111 Mobile station communication part 112 Mobile station baseband part 112a Mobile station baseband part 113 Mobile station control part 401,402,403,412,413 Area 501, 502, 503, Line 511, 521 Band

Claims (6)

A communication device that performs wireless communication using the LTE method according to the 3GPP standard ,
A communication unit that transmits an LTE transmission signal in a transmission frequency band defined by the PHS method ;
The transmission frequency band is adjacent to an adjacent frequency band for another system;
There is no guard band between the transmission frequency band and the adjacent frequency band, and a band apart from the center of the transmission frequency band by a certain frequency is in the adjacent frequency band,
When the communication unit transmits an LTE transmission signal in the transmission frequency band, the maximum transmission power is limited more than the spectrum mask specified in the 3GPP standard, and the transmission power radiated to the band apart from the constant frequency is communication device, characterized by the following thresholds of fixed corresponding to the provision of the leakage power to the other systems. The communication apparatus according to claim 1, wherein the fixed threshold value is a threshold value corresponding to a definition of a PHS method. The band apart from the constant frequency is the first band, the band further away from the constant frequency is the second band, and the first band and the second band are in the adjacent frequency band,
Wherein the threshold value of the fixed and the first threshold value, the lower value than the first threshold value and second threshold value,
When the communication unit transmits a transmission signal of the LTE system in the transmission frequency band, the transmission power to be radiated to the second band to claim 1 or 2, characterized in that below said second threshold value The communication device described. The transmission power radiated to the first band and the second band by the communication unit is smaller than the transmission power of the first band and the second band corresponding to a spectrum mask defined by 3GPP. The communication device according to claim 3 . A communication method for a communication device that performs wireless communication using LTE according to the 3GPP standard ,
An LTE transmission signal is transmitted in a transmission frequency band defined by the PHS system,
The transmission frequency band is adjacent to an adjacent frequency band for another system;
There is no guard band between the transmission frequency band and the adjacent frequency band, and a band apart from the center of the transmission frequency band by a certain frequency is in the adjacent frequency band,
When transmitting an LTE transmission signal in the transmission frequency band, the maximum transmission power is limited more than the spectrum mask defined in the 3GPP standard, and the transmission power radiated to the band apart from the constant frequency is transmitted to the other system. to the below threshold value fixed corresponding to the provision of leakage power
A communication method characterized by the above . A communication system that includes a communication device and a partner communication device, and performs wireless communication by LTE according to the 3GPP standard ,
The communication device transmits an LTE transmission signal in a transmission frequency band defined by the PHS method ,
The transmission frequency band is adjacent to an adjacent frequency band for another system;
There is no guard band between the transmission frequency band and the adjacent frequency band, and a band apart from the center of the transmission frequency band by a certain frequency is in the adjacent frequency band,
When the communication apparatus transmits an LTE transmission signal in the transmission frequency band, the transmission power restricts the maximum transmission power from the spectrum mask defined in the 3GPP standard and is radiated to the band apart from the constant frequency. communication system, characterized by the following thresholds of fixed corresponding to the provision of the leakage power to the other systems.